The active opto-electronic components concerned by the invention are light-producing or light-detecting components which may be coupled to conductors of integrated circuits. The opto-electronic component may particularly be a semiconductor component, a laser diode, a light-emitting diode, a photodiode, or a phototransistor, for example. In order to associate this opto-electronic component with an optical fiber with optimal coupling, it is necessary to align the optical axis of the optical fiber on the optical axis of the opto-electronic component with extreme accuracy. However, due to the very small dimensions of the opto-electronic components, adjusting the alignment of the optical axes of the optical fiber and opto-electronic component is a very delicate operation, because in some cases it requires accuracy on the order of or greater than 1 μm in all three axes. This is why this alignment is generally adjusted dynamically, and the optical fiber moved with a micromanipulator is adjusted in position, with the opto-electronic device being operating.
The quality of the resulting coupling, meaning the ratio of the signal transferred by the coupling over the signal transmitted by the input optical fiber in the event of input coupling, is higher if the positioning of the optical fiber's end relative to the opto-electronic component is well-adjusted. In practice, this requires very accurate positioning of the optical fiber relative to the opto-electronic component. The optical fiber's position relative to the opto-electronic component must then remain optimal while fastening the optical fiber onto its mount.
One known method is based on moving the optical fiber along three orthogonal axes, one of which is parallel to the optical axis of the opto-electronic component and the other two of which are perpendicular to that same axis: the adjustment is therefore performed in a system of Cartesian coordinates. When the alignment is obtained, the parts are fixed in place by laser welding. The drawback of this method is that it requires precision-machined smooth surfaces, which makes it expensive.
To remedy this drawback, it has been proposed to use polar coordinates. The opto-electronic component is fastened on a base that comprises grooves, and the optical fiber is held between plates resting on those grooves.
To remedy this drawback, it has also been proposed to have a device using lower-precision parts, the optical fiber being tilted and moved in order to obtain optimal coupling. The opto-electronic component is fastened on a base that comprises a slot, and the optical fiber is locked in place by a keyhole-shaped pincher whose tips are inserted into the slot.
Another method consists of moving the optical fiber, placed facing the opto-electronic component, within a solidifiable product. This solidifiable product is either melted soft solder, or polymerizing glue. The optical fiber's position is adjusted until the maximum transferred signal is obtained, then the product is solidified when optimal coupling is reached; in this matter, it is fastened into an appropriate position. The drawback of this method is that while the product is solidifying, forces of contraction move the optical fiber and may sometimes even break it. In order to keep from reducing the coupling, the movement caused by the shrinkage is anticipated when positioning the optical fiber relative to the opto-electronic component. Nonetheless, shrinkage is not always foreseeable, and the resulting alignment does not have the required accuracy.